10.6084/m9.figshare.1012492.v1 A Rouzée A Rouzée F Tavella F Tavella H Redlin H Redlin S Düsterer S Düsterer Y Huismans Y Huismans W Siu W Siu A Hundertmark A Hundertmark L Rading L Rading P Johnsson P Johnsson N Stojanovic N Stojanovic Magnified portion of panel (e) of figure 5, highlighting the Coulomb explosion dynamics IOP Publishing 2013 xuv Coulomb explosion imaging MFPAD FEL pulse Coulomb explosion channels mf cei velocity map imaging spectrometer flash CO 2 molecules Coulomb explosion dynamics Free Electron LASer dissociation dynamics Br 2 sample pad Br 2 molecules Atomic Physics Molecular Physics 2013-08-13 00:00:00 Figure https://iop.figshare.com/articles/figure/_Magnified_portion_of_panel_e_of_figure_a_href_http_iopscience_iop_org_0953_4075_46_16_164029_articl/1012492 <p><strong>Figure 6.</strong> Magnified portion of panel (e) of figure <a href="http://iopscience.iop.org/0953-4075/46/16/164029/article#jpb465815f5" target="_blank">5</a>, highlighting the Coulomb explosion dynamics. The white interconnected dots show the fragment energies predicted by the classical model for three different Coulomb explosion channels: Br<sup>2 +</sup>+Br<sup>+</sup>, Br<sup>2 +</sup>+Br<sup>2 +</sup> and Br<sup>2 +</sup>+Br<sup>3 +</sup>.</p> <p><strong>Abstract</strong></p> <p>The dissociation dynamics induced by a 100 fs, 400 nm laser pulse in a rotationally cold Br<sub>2</sub> sample was characterized by Coulomb explosion imaging (CEI) using a time-delayed extreme ultra-violet (XUV) FEL pulse, obtained from the Free electron LASer in Hamburg (FLASH). The momentum distribution of atomic fragments resulting from the 400 nm-induced dissociation was measured with a velocity map imaging spectrometer and used to monitor the internuclear distance as the molecule dissociated. By employing the simultaneously recorded in-house timing electro-optical sampling data, the time resolution of the final results could be improved to 300 fs, compared to the inherent 500 fs time-jitter of the FEL pulse. Before dissociation, the Br<sub>2</sub> molecules were transiently 'fixed in space' using laser-induced alignment. In addition, similar alignment techniques were used on CO<sub>2</sub> molecules to allow the measurement of the photoelectron angular distribution (PAD) directly in the molecular frame (MF). Our results on MFPADs in aligned CO<sub>2</sub> molecules, together with our investigation of the dissociation dynamics of the Br<sub>2</sub> molecules with CEI, show that information about the evolving molecular structure and electronic geometry can be retrieved from such experiments, therefore paving the way towards the study of complex non-adiabatic dynamics in molecules through XUV time-resolved photoion and photoelectron spectroscopy.</p>